diff --git a/libc/platform/bionic/android_unsafe_frame_pointer_chase.h b/libc/platform/bionic/android_unsafe_frame_pointer_chase.h
index 2b9a32f..406ad92 100644
--- a/libc/platform/bionic/android_unsafe_frame_pointer_chase.h
+++ b/libc/platform/bionic/android_unsafe_frame_pointer_chase.h
@@ -44,4 +44,4 @@
  * take stack traces efficiently. Normal applications should use APIs such as libunwindstack or
  * _Unwind_Backtrace.
  */
-extern "C" size_t android_unsafe_frame_pointer_chase(uintptr_t* buf, size_t num_entries);
+extern "C" size_t android_unsafe_frame_pointer_chase(uintptr_t* _Nonnull buf, size_t num_entries);
diff --git a/libc/platform/bionic/fdtrack.h b/libc/platform/bionic/fdtrack.h
index fe6ca84..7fc304a 100644
--- a/libc/platform/bionic/fdtrack.h
+++ b/libc/platform/bionic/fdtrack.h
@@ -43,6 +43,8 @@
   ANDROID_FDTRACK_EVENT_TYPE_CLOSE,
 };
 
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wnullability-completeness"
 struct android_fdtrack_event {
   // File descriptor for which this event occurred.
   int fd;
@@ -57,12 +59,15 @@
     } create;
   } data;
 };
+#pragma clang diagnostic pop
 
 // Callback invoked upon file descriptor creation/closure.
-typedef void (*android_fdtrack_hook_t)(struct android_fdtrack_event*);
+typedef void (*_Nullable android_fdtrack_hook_t)(struct android_fdtrack_event* _Nullable);
 
 // Register a hook which is called to track fd lifecycle events.
-bool android_fdtrack_compare_exchange_hook(android_fdtrack_hook_t* expected, android_fdtrack_hook_t value) __INTRODUCED_IN(30);
+// Set value to null to disable tracking.
+bool android_fdtrack_compare_exchange_hook(android_fdtrack_hook_t* _Nonnull expected,
+                                           android_fdtrack_hook_t value) __INTRODUCED_IN(30);
 
 // Enable/disable fdtrack *on the current thread*.
 // This is primarily useful when performing operations which you don't want to track
diff --git a/libc/platform/bionic/macros.h b/libc/platform/bionic/macros.h
index 9e13e0d..93268c1 100644
--- a/libc/platform/bionic/macros.h
+++ b/libc/platform/bionic/macros.h
@@ -40,12 +40,12 @@
 }
 
 template <typename T>
-static inline T* align_down(T* p, size_t align) {
+static inline T* _Nonnull align_down(T* _Nonnull p, size_t align) {
   return reinterpret_cast<T*>(align_down(reinterpret_cast<uintptr_t>(p), align));
 }
 
 template <typename T>
-static inline T* align_up(T* p, size_t align) {
+static inline T* _Nonnull align_up(T* _Nonnull p, size_t align) {
   return reinterpret_cast<T*>(align_up(reinterpret_cast<uintptr_t>(p), align));
 }
 
@@ -94,6 +94,6 @@
 }
 
 template <typename T>
-static inline T* untag_address(T* p) {
+static inline T* _Nonnull untag_address(T* _Nonnull p) {
   return reinterpret_cast<T*>(untag_address(reinterpret_cast<uintptr_t>(p)));
 }
diff --git a/libc/platform/bionic/malloc.h b/libc/platform/bionic/malloc.h
index 3c290fc..0a6546e 100644
--- a/libc/platform/bionic/malloc.h
+++ b/libc/platform/bionic/malloc.h
@@ -33,7 +33,8 @@
 #include <stdint.h>
 
 // Structures for android_mallopt.
-
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wnullability-completeness"
 typedef struct {
   // Pointer to the buffer allocated by a call to M_GET_MALLOC_LEAK_INFO.
   uint8_t* buffer;
@@ -47,7 +48,7 @@
   // The maximum number of backtrace entries.
   size_t backtrace_size;
 } android_mallopt_leak_info_t;
-
+#pragma clang diagnostic pop
 // Opcodes for android_mallopt.
 
 enum {
@@ -105,6 +106,8 @@
 #define M_MEMTAG_STACK_IS_ON M_MEMTAG_STACK_IS_ON
 };
 
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wnullability-completeness"
 typedef struct {
   // The null-terminated name that the zygote is spawning. Because native
   // SpecializeCommon (where the GWP-ASan mallopt() is called from) happens
@@ -147,9 +150,9 @@
 
   Action desire = DONT_TURN_ON_UNLESS_OVERRIDDEN;
 } android_mallopt_gwp_asan_options_t;
-
+#pragma clang diagnostic pop
 // Manipulates bionic-specific handling of memory allocation APIs such as
 // malloc. Only for use by the Android platform and APEXes.
 //
 // On success, returns true. On failure, returns false and sets errno.
-extern "C" bool android_mallopt(int opcode, void* arg, size_t arg_size);
+extern "C" bool android_mallopt(int opcode, void* _Nullable arg, size_t arg_size);